A testament to a good single is its longevity in the charts and it looks like Mariah Carey's Christmas classic, 'All I Want For Christmas Is You' could be well-placed for the best Christmas song of all time as sales of the 1994 track quickly approach one million copies in the United Kingdom.

The song is Mariah's biggest single to date, with an estimated 12 million copies sold worldwide, also making it one of the highest-selling songs of all time. However, upon its release in 1994, Mariah was pipped to the post in the charts by London boyband East 17 and their 'Stay Another Day.'

After selling a respectable 306,000 copies in six weeks, 'All I Want For Christmas.' dropped out of the top 40. Thanks to digital downloads and the song's firm reputation as a Christmas karaoke must-have, the heart-warming track returned to the Official Singles Chart some 13 years after its original release to peak at Number 4 and has similarly re-emerged every December since 2007, according to the Official Charts Company.

With its festive theme and flirtatious message, Mariah's holiday single has stood the test of time and seems to have lost little of its appeal. The music video may show a much younger Mariah cavorting in the snow but the modern day diva, now 43, is still raking in the cash from this canny release.

Of course, the continued festive appeal of 'All I Want For Christmas.' is only solidified by its prominent use in movies (See: 'Love Actually') as well as countless cover versions performed by big name artists, including Michael Bublé, Justin Bieber and Miley Cyrus.

In 2013, Mariah's voice is still one of the most desirable to have at high profile holiday events at this time of year, having performed at the recent 81st Annual Tree Lighting held at New York's Rockefeller center and once again dazzling the crowds and NBC viewers with her big voice and glamour.

So after you've necked those snowballs this year and have been egged on to the microphone, take a breath before you belt out this Christmas classic and listen for the jingling.of Mariah Carey's royalties.